Thank you for your post and welcome to the Community!
In regards to your query, the Soundbar 500 is not able to connect to the Companion 3 series II. I apologize for any inconvenience this may cause you.
If you have any further questions, feel free to reach out to us again!
Jessie O - Community Support
Feel more. Do more. Be more. Come check out my profile here. New to the community? Check out the Getting Started board. Help others find answers to your questions by clicking on 'Accept as Solution' at the bottom of a reply. If you see a post you like, make sure to give it a thumbs up!